ata: fixup ATA_PROT_NODATA

The taskfile protocol is a numeric value, and can not be ORed.  Currently
this is harmless as the protocol is always zeroed before, but if it ever
has a non-zero value the ORing would create incorrect results.
Signed-off-by: Hannes Reinecke <hare@suse.de>
[hch: updated patch description]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

drivers/ata/libata-core.c

@@ -1238,7 +1238,7 @@ static int ata_read_native_max_address(struct ata_device *dev, u64 *max_sectors)
 	} else
 		tf.command = ATA_CMD_READ_NATIVE_MAX;
 
-	tf.protocol |= ATA_PROT_NODATA;
+	tf.protocol = ATA_PROT_NODATA;
 	tf.device |= ATA_LBA;
 
 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
@@ -1297,7 +1297,7 @@ static int ata_set_max_sectors(struct ata_device *dev, u64 new_sectors)
 		tf.device |= (new_sectors >> 24) & 0xf;
 	}
 
-	tf.protocol |= ATA_PROT_NODATA;
+	tf.protocol = ATA_PROT_NODATA;
 	tf.device |= ATA_LBA;
 
 	tf.lbal = (new_sectors >> 0) & 0xff;

drivers/ata/libata-eh.c

@@ -3177,7 +3177,7 @@ static void ata_eh_park_issue_cmd(struct ata_device *dev, int park)
 	}
 
 	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
-	tf.protocol |= ATA_PROT_NODATA;
+	tf.protocol = ATA_PROT_NODATA;
 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
 	if (park && (err_mask || tf.lbal != 0xc4)) {
 		ata_dev_err(dev, "head unload failed!\n");